July 25th, 2011
05:07 PM ET
Lab tests to determine what killed singer Amy Winehouse will take two to four weeks, according to the Scotland Yard.
Unlike television crime shows where results are instant, standard toxicology tests can require several steps, taking up to several weeks.
An autopsy completed Monday afternoon was inconclusive and investigators will need the toxicology results to determine the singer’s cause of death, according to a police statement.
Toxicology tests are used to determine whether and how much legal or illegal drugs a person has taken. While it’s unclear what caused Winehouse’s death, her erratic behavior and drug problems were public after she reached musical stardom in 2007.
In post-mortem toxicology screenings, blood is drawn from various areas of the deceased person’s body. This initial test indicates what type of drugs, such as opiates or amphetamines, might be present.
The secondary part is where it becomes complicated.
Drug analysis a multistep process
“You confirm the preliminary test,” said Douglas Rohde, supervisor of chemistry and toxicology at the Lake County Crime Lab in Ohio. “You confirm that drug is actually there. There’s not one test as seen in 'CSI.' There’s no quick test that gives you a positive identification and confirmation. The confirmatory tests can take days or weeks, if they have to be repeated.”
To confirm that a person had a type of drug in his or her body, the drug has to be separated from the blood or tissue.
The gold standard for drug identification is gas chromatography-mass spectrometry, an instrument that looks at drugs at the molecular level. Its even more advanced version is called liquid chromatography tandem mass spectrometry.
“You go through and run individual tests, running a specific test to get a level of a specific drug,” said Dr. Daniel Spitz, chief medical examiner in Macomb and St. Clair Counties in Michigan.
This process could take several days depending on the types of drugs found in the body. And drugs could be present in very minute levels, in measurements like parts per million or parts per billion. Rohde likens it to searching for five black marbles in a pile of 1 million white marbles.
In the final step, the toxicologist reviews the evidence and determines whether drugs found in the body were enough to kill an individual. That report is submitted to the coroner or medical examiner, at least in the United States.
Cases involving Michael Jackson, Heath Ledger and Anna Nicole Smith were complicated because they had several different drugs in their bodies - some of the substances “weren’t in the regular menu in the toxicology lab,” Rohde said.
“Anytime you have a notorious person die of suspect means and they have past history of drug abuse, the toxicology report is very important,” he said. “You don’t want to rush it.”
In a high-profile case like Winehouse's, it is most likely that the lab will run several tests to confirm its findings.
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